Pneumatic tube and method of making the same



May 8, 1923- W. P. PORTER PNEUMATIC TUBE AND METHOD OF MAKING THE saw:

Filed Jan. 30, 1922 ?atented May 8, $23.

rattan WINFIELD P. PORTER, OF NEW YORK, N. Y.

PNEUMATIC TUBE AND METHOD OF MAKING THE SAME;

Application filed January 30,1922. Serial No. 532,703.

To all whom it may camera:

Be it knownthatl, lVI NrInLn P. PORTER,

a citizenof the United States, a resident of the city of New York, inthe county of the Bronx and State of New York, have invented a certain new and useful'lmproved Pneumatic Tube and Method of Making the Same, of which the following is a specification.

' The invention relates to an inflatable inner tub for tires of the type wherein the tube is reinforced to minimize the danger of blowouts by a plurality of reinforcing strands or strips of fabric or the like, and yet such strips or strands are so related to each other and tothe body of the tube that the elasticity of the tube, both as regards longitudinal and lateral expansion or contraction, is not impaired. In other words, the tube is left free, notwithstanding the reinforcement to adjust-itself, both in length or perimeter and in diameter or cross-sectional area. I 'T One object of the invention is to provide a tube of the above ichara'cter of such struc-' ture as to facilitate its manufacture and the operations involved therein, particularly with regard to theproper disposition of the reinforcement in the walls of the tube.

The invention also includes a tube of the above type possessing reinforcement against rupture in all directions-without impairment toits expansibility oradjustability above described.

Further objects and advantages of the invention will be in part obvious and in part specifically pointed out in. the descriptlon hereinafter contained,'which, taken in connection with the accompanying drawings,

, 40 discloses a preferred embodiment thereof;

such embodiment, however, is to be considered merely as illustrative of its principle.

In the drawings-- Figure 1 is a view of a portion of a web of elastic material reinforced with strands such as are adapted for use in the invention,

such view indicating the manner. in which a web of the above character may be cut up to rovide pieces for assemblage to form a'tube in accordance with the invention;

Fig. 2 is an edge view of the web shown in Fig. 1;

Fig. 3 is a yiew showing pieces of the character obtained from the web illustrated in Fig. 1, juxtaposed and porated in the body of the tube, each of such united according to the method of making the tube;

'Fig. 4 is an edge view of the structure 7 shown in Fig. 3; Fig. 5 is a top view of a tube made in accordance with the invention' Fig. 6 is aside view of a composite tube of the above character constructed to provide reinforcement against rupture in all directions, certain portions of the tube being cut away; H

Figs. 7,8 and 9 are, respectively, crosssectional, side and'bottom views of the tube shown in Fig. 5. v I

In my prior United States Patent No. 1,394,787. dated October 25, 1921, and en- 7 titled Pneumatictire, I have shown an; inn'er tube of the above type-whereinthe reinforcement is. obtained by strips'jjpr strands of relatively, strongmaterial incor, 75.. strands having an intermediate portion at, the belly of the tube and its end portions extending around the sides thereof at. an inclination to the longitudinal axis of the tube, such end portions crossing at the tread,. whereby the reinforcement takes the form of a series of parallel inclined Vs having their bases at the belly of the tube and their 'end's crossing at the tread. As a tube of the above type is inflated, the reinforcement be comes in clined less and less to a radial section through the tube, and such reinforcement permits-proper expansion of its resilient walls, since as the Vs become less and less inclined, an increase in diameter of the tube results; furthermore, such Vs being also inclined to the longitudinal axis of the. tube, permit the elastic material between the strands of the reinforcement to stretch and thus afford an increase in the perimeter 95 of thetube conformable to its increasein radial section. a r I However, some diificulty is involved in; incorporating the reinforcement into the elastic material of such a tube in case the-1 operation involves forming the reinforcing 9 side by side into v'or other. angiilar shape is avoided'and' yet the tube-resulting from the steps or available reinforcing materials,

. fabric, Binay be employed.

j trated in Fig. 1 a Web 1 of'ela'stic materi'al 2 and coating the same on opposite sides methods of manufacturevhereinafter spec1- fied is reinforced insucha manner as to provide the desired expansibility. In the.-

preferred'formof the invention, the tube is furthermore, so constructed -"that readily Referring to the drawings, I have illussuch as rubber or rubber composition, having incorporated therein a plurality of par allel, slightly spaced, reinforcing strands 2.- The Web shown in Fig. 1 may be obtained by laying down wholly unconnected strands I with, rubber oruhe like, but I prefer teem- .proper relation to each ex'pansibility I In other Words,

' in Figs. 5 to 9. of the -drawjings.'

v pieces are oppositely, inclined inforcing strands a cord'fabric for this purpese, such fabric consisting of the longitudinal or warp reinforcing strands 2 tied together by means ofiine Weft threads 3' which serve to insure that the strands other during, the operation of forming the yvebja nd which are yet so fragile as to have no effect .upon the the'fine threads 3 are so Weakthat they become severed as soon as any substantial strain is placed uponthem. Such threads, therefore, are not illustrated The Web' f material such as above dc scribed may 'then be 'cut on the bias to provide a plurality of pieces 4, each piece have 1 ing, the reinforcing strands). running at an angle to the side edges thereof. As indicated in Fig. .3, pieces/4 of the character above. described may then be laid down the reinforcing strands 2 in therespective' .to the adedges of the pieces; "such side jacent side then suitably secured together,

edges are beingslightly overlapped,- if' desired, and y, cemented by strips of rubber 5 (Fig. 4') placed along both sides of the juncture.

Thus the reinforcedelastic sheet made up of pieces i above described will contain re d which are of angular or K -.V-shape.and--yet the expensive and difficult operations of forming individual strands into such shape is avoided.

The reinforced sheet may then be suitably formed into tub'ularshapes-for example,

by Wrapping the same aroundfa pole with the apices of the angles between the reinforcing strands '2 at the belly 'of the tube tobe'formed and the side 'edges'of thesh'e'et' overlapping at thetread thereof, whereby the reinforcing strands in tlie: alioye-mcn'- tioned sides of the sheet will form a,1cr o'sse,d-

3 reinforcement. in the. tread of -Hi3 tube:

' The tube may .thenzbe vulcanized "and cured n any suitable manher,,tor example,-

such as cor'd' distinguishable.

2 will be maintained inof the tube after completion.

with "one piecereversed so that above-1ncn'tioned adjacent ends strands are located :at'the belly of the tube,

as described in my prior Patent l lo. 1,394,-

787 above-mentioned, a compression tread 6 (Fig, I being built up upon the overlappingsides of the sheet, if desired,' so as to protect he tube against puncture. For clearness, the outlines of the overlapping sides of the reinforced sheet are preserved in Fig. 5 to show more plainly the relation of the parts of the sheet in the conipleted roduct, but it will be understood that after t 1e tube has been vulcanized and cured as above described. such outlines will be in- The lower end of the sheet,'as the-same appehrsin' Fig.5, isalso cut parallel to the-length of the reinforcing strands 2 to indicate the inclination of-such strands to a radial-section of the tube.

Thus it will be selen that thejsides of the completed tube are reinforced by a plurality of strands which 'run inclined to both thelongitudinal and transverse dimensions of theitube and thereby permit proper changes of shape therein. In some instances, particularly \vherera tube is to'be employed upon vehicles carrying Veryheavy loads, it may be desirable to reinforce the tube, particularly at its sides, rupture due to blowouts, and

2 extending in. one'direction and an'outer-"' I tube hfreely movable with reference to the inner tube 7 and having its reinforcing strands? oppositely inclined so asgtq cross.

over the strands 2* previously) described. Thus, asthe-composite tube'isinfiated, both tubes 7 and Smay expand freely and yet the crossed reinforcing strands 2v and 2"-=-Will provide reinforcement against blowoutsin all directions. If desired, the tubes 7 and 8 may be unitedadjacentthe usualyalve 9-to maintain the latter in proper position lot From the foregoing description it will,

be noted that an inner "tube having reinforcing strands disposed in accordance with athe".

invention will conta'iuone group of such strands extending partially aroundthe tube in a diagonal direction,-for example,- the strands shown at the right of Fig. f5, and

another group of similar strands extending.

around; another .portion of. the tube from points adjacent one of the ends -of the fi-r'stgroup. This last-mentioned -group of strands; for example; vill be the mentioned strands at the left of Fig. ,5. In the illustrated embodiment of the invention, the

While they remaining'ends of such groups of of the -strands overlap at the tread'toform a I crossed reinforcement therein. v :While a specific embodiment of the invention has been described, it is obvious that many ch'an es may be made therein Without departing rom the spirit of the invention as defined in the following claims.

What I claim and desire to secure by Letters Patent is:

1. The method of making an inner tube which comprises uniting side edges-of pieces of elastic material containing parallel reinforcing strands running at opposite angles to such side edges to make up a sheet and forming such sheet into a tube.

2. The method of making an inner tube which comprises uniting side edges of pieces of elastic material containing parallel reinforcing strands running at opposite angles to such sides to make up a sheet having a V-shaped reinforcement and forming such sheet into a tube.

3. The method of making an inner tube which comprises uniting side edges of pieces of elastic material containing parallel reinforcing strands running at opposite angles to such sides to make up a sheet having a V-shaped reinforcement, folding such sheet into tubular shape with the apices of the aforesaid angles at the belly of the tube and the remaining side edges of the sheet-at the tread of the tube. f

4. The method of making an inner tube which comprises uniting side edges of pieces of elastic material containing parallel reinforcing strands running at opposite angles to such sides to make up a sheet havinga V-shaped reinforcement, folding such sheet into tubular shape with the apices of the aforesaid anglesat the belly of the tube and the remaining side edges of the sheet overlapping substantially at thetread of the tube, whereby the reinforcing strands in the abve-mentioned sides of the sheets form a crossed reinforcement in the tread.

5. The method of making an inner tube which comprises severing on the bias a Web of elastic material containing parallel reinforcing strands to form pieces with the strands running at an angle to side edges thereof, uniting side edges of such pieces with the strands oppositely. inclined to such edges to make up a sheet and forming such sheet into a tube. a

6. An inner tube having elastic-walls. a groupof parallel reinforcing strands therein extending only partially around the tube and diagonally inclined to the length thereof, and another group of parallel reinforcing strands extending only partially around from points adjacent one of the ends of said first-mentioned group, said last-mentioned group of strands being also diagonally inclined to the length of the tube, and the adjacent ends of said groups being angularly related.

around one side to the tread thereof, such strands being diagonally inclined to the length of the tube, and another group c; parallel reinforcing strands extending from the belly of the tube around the other side ,thereof to the trca(l,'sa id last-mentioned group of strands being similarly diagonally inclined to the length of the tube, whereby the adjacent. ends of said groups form a V-shaped reinforcement with their apices at the belly of the tube.

8. An innexytube having elastic walls, a group of parallel reinforcing strandstherein extending from the belly of the tube around one side to the tread thereof, such strands being diagonally inclined tothe length of the tube, and another group of'parallel reinforcing strands extending from the belly of the tube around the other side 'thereof to the tread, said last-mentioned group of strands being similarly diagonally inclined to the length of the tube whereby the adjacent ends of said groug'is form a V-shaped reinforcement with their apices at the belly of the tube, the remaining ends of said groups of strands being overlapped to cross at the tread.

9. A composite inner tube comprising an inner tubular member having elastic Walls, parallel reinforcing strands extending around the sides of such member and similarly diagonally inclined to thelength thereof on opposite sides of the tube, and an outer tubular member having similar reinforcing strands thereon butinclined in the opposite direction from the strands of the first-mentioned tubular member, said members being free to shift relative to each other and being substantially unconfined except for the reinforcing strands aforesaid.

10. A composite inner tube comprising an inner tubular member having elastic walls, parallel reinforcing strands in said walls extending around the sides of such memberand providinga V-shaped reinforcement similarly inclined to the length of the tube on opposite sides thereof and with the apices of the V at the belly thereof, and an outer -tubular member having similar reinforcing strands therein but inclined in the, opposite direction from the strands of the first-mew tioned tubular free to shift relative-to each other and being substantially unconfined except for the reinforcing strands aforesaid.

member, said members being in said walls I in testimony that I claim the foregoing, I have hereunto set my hand this 19th day of January, 1922.

WINFIELD P. PORTER. 

